footer {  
  position: absolute;
  bottom: 0px;

  width: 100%;
  height: 43px;
  background-color: rgb(70, 70, 70);

  display: flex;
  align-items : center;  
}

/* 字数 */
footer .word-count {  
  padding: 3px 7px;
  background-color: #fff;
  margin-left: 50px;
  
  color: black;
  font-weight: 700;
}
/* 行数 */
footer .line-number {
  padding: 3px 7px;
  background-color: #fff;
  margin-left: 50px;
  
  color: black;
  font-weight: 700;
}

/* 返回顶部 */
footer .return-top {      
  position: absolute;
  right: 100px;

  padding: 3px 7px;
  background-color: #fff;
  margin-left: 50px;
  
  color: black;
  font-weight: 700;

  cursor: pointer;
}



